Refrigerating machine



April 17, 1934. c. sTEENsTRUP REFRIGERATING MACHINE Filed Nov. 5. 1952 Fig I..

Fig Z Invent or: Christian Steenstrup,

9 I-II s Attorrweg.

Patented Apr. 17, 1934 UNITED STATES PATENT OFFICE REFRIGERATIN G MACHINE tion of New York Application' November 5, 1932, serial No. 641,395l

15 Claims.

My invention relates to refrigerating machines and particularly to refrigerating machines of the type having a valveor flow controlling device for the purpose of admitting refrigerant to the low pressure side of the system from the high pressure side thereof.

In connection with refrigerating systems adapted to cool a compartment, such as a domestic refrigerator, an evaporator which is supplied with a refrigerant from some external source is ordinarily placed Within 'the compartment. It is necessary to provide a device for controlling the flow of refrigerant to the evaporator such as a valve, an orice or the like, which maintains the necessary difference of pressure between the evaporator and the source of refrigerant supply. When the refrigerant passes from the high pressure side of the machine through this flow controlling device to the low pressure side thereof,

a portion of the refrigerant vaporizes due to the sudden decrease in pressure and absorbs heat from the liquid refrigerant and from the adjacent parts of the system and the surrounding media.

If the liquid refrigerant is cooled to approximately the temperature of the refrigerator compartment, the cooling effect of the refrigerant vaporizing at the iiow controlling device is available to cool the compartment. The eiciency of the refrigerating system may thus be increased.

An object of my invention is to provide an improved refrigerating system which makes use of a now controlling device arranged so that the heat which tends to flow thereto from the other parts 3 of the refrigerating system operating at higher temperature, is absorbed before it reaches the flow controlling device.

Another object of my invention is to provide an 40 improved refrigerating system utilizing the heat absorbing capacity of the vaporized refrigerant which is removed from the evaporating unit for the purpose of absorbing the heat which tends to ow to the flow controlling device from parts of the refrigerating system operating at a higher temperature.

A further object of my invention is to provide an improved fioat operated valve for controlling the' flow of refrigerant in refrigerating systems in which the refrigerant supplied to the valve from the ow chamber is pre-cooled.

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

In the accompanying drawing Fig. 1 is a side elevation of a mechanical refrigerating system embodying my invention; Fig. 2 is a front eleva- 50 tion of a refrigerating cabinet incorporating a refrigerating system embodying my invention; and Fig. 3 is an enlarged sectional elevation of a float valve and heat exchanger constructed in accordance with my invention. 55

Referring now to the drawing, in Figs. 1 and 2,

I have shown my invention in connection with a refrigerating system which is mounted on the top 10 of a compartment to be cooled. This refrigerating system is shown in Fig. 2 arranged to cool 70' a household refrigerator which is shown with the door open giving a side elevation of Fig. 1. This refrigerating system includes a cooling unit or evaporator li attached to the inner wall 12 of the top l0 and which is arranged to cool the 75 compartment below the top l0 and also to make ice or freeze other articles placed within the evaporator. The system also includes a motor and compressor unit arranged within an enclosing casing 13 mounted on the top 10. Gaseous 80 refrigerant is compressed by the compressor in the casing 13 and passes through a connection 14 in to the coiled condenser 15 supported on cooling fins 16 in spaced relation to the casing 13. The compressed refrigerant in passing through the condenser coil 15 is cooled and condensed into a liquid and then flows through the connection 17 into a float Valve chamber l8 which is mounted in the top 10 and embedded in insulation 19. The liquid refrigerant accumulates in the oat valve chamber 18 and actuates a float therein to control the flow of liquid refrigerant through the conduit 20 into the header 21 of the evaporator 11. The liquid refrigerant in the evaporator 11 absorbs heat from the refrigerator 95 compartment and is vaporized and is then withdrawn from the evaporator by the compressor through the conduit 22 and a heat exchanging device 23 embodying my invention. This cycle of operation is continuously repeated during operation of the machine.

The particular construction of the float valve and heat exchanger assembly is best seen in Fig.

3. The float valve chamber 18 comprises an inverted cup-shaped receptacle 25, which is brazed or welded to a base 26. This receptacle is welded in a flanged opening in the top Wall 27 of the refrigerator top 10, as indicated at 28, and is embedded in the insulating material 19 arranged between the upper Wall 27 and the lower wall 110 12 of the top 10. The valve 29, which controls the flow of liquid refrigerant from the float valve chamber 18 to the evaporator 11 is controlled by a float 30, which is sldably mounted on a guide rod 31 supported within the chamber 18. This guide rod is supported in a lower seat 32 and is secured at its upper end by an adjustable fitting which is not shown in the drawing, and which retains it in place against the action of the compression spring 33 arranged between the base 26 of the valve chamber 18 and a disc 34 secured to the guide rod 31. During ordinary operation the float 30 rises and falls in accordance with variations in the level of the liqudrefrigerant in the float valve chamber, and the movement of this float is utilized to control the opening and closing of the valve 29 between the float valve chamber and the evaporator by providing a linkage connecting the float with the valve 29.

It will be understood that the float chamber 18 is subject to the high temperature and pressure in the condenser 15 of the refrigerating system, and that the evaporator l1 is maintained at low temperature and pressure by the compresser, so that the liquid refrigerant in the evaporator is vaporized at the desired rate. When the float rises and liquid refrigerant passes through the valve 29 a portion of this refrigerant is suddenly vaporized because of the reduction 1n pressure to which it is subjected, and absorbs heat which lowers the temperature of the valve and the surrounding parts of the system, because of the reduced temperature at the valve, it is desirable to locate this valve Within the cabinet to be cooled in order to utilize the heat absorbing capacity thereof.

In mechanical refrigerating machines the eiliciency increases with decrease in the temperature of the condenser and consequent decrease in the temperature of the liquefied refrigerant. The gaseous refrigerant withdrawn from the evaporator is at a temperature considerably below that of the liquid refrigerant delivered by the condenser. In accordance with my invention, I provide a heat exchanger 23 to conduct the gaseous refrigerant extracted from the evaporator into heat exchanging relation with the liquid refrigerant as it flows from the float chamber to the valve 29. The heat exchanger 23 comprises a cylindrical casing 35 which surrounds and is spaced from a tube 36 which conveys liquid refrigerant from the float valve chamber 18 to the valve 29. Between the tube 36 and the cylindrical casing 35 is arranged a helically wound iin 3'7 which forms a helical path by which the gaseous refrigerant must pass in going through the heat exchanger 23. The gaseous refrigerant is withdrawn from the evaporator 11 through the conduit 22 and enters the heat exchanger 23 at the bottom thereof, and then passes up through the heat exchanger, absorbing heat from the downwardly flowing liquid refrigerant whence it passes out through the conduit 24 to the compressor within the casing 13. The body of liquid refrigerant within the tube 36 is cooled by this passage of gaseous refrigerant through the helical path within the heat exchanger 23, and as a result the heat absorbing capacity of the liquid regrigerant is increased as is also the eflice'ncy of the refrigerating cycle, because of the reduced heat content of the liquid refrigerant supplied to the evaporator.

During operation of the mechanical refrigerat` ing system shown in the drawing, the liquid refrigerant supplied by the condenser 15 accumulates within the float chamber 18 as it is liquefied. If the parts of the float valve are in the position shown in Fig. 3 the liquid refrigerant will flow through the valve 29 until suilicient has passed to permit the float 30 to drop and close the valve 29. As the liquid refrigerant passes through the valve, a portion of it will evaporate due to the drop in pressure and will absorb heat. As the tube 36 is surrounded by the heat exchanger 23, the liquid refrigerant therein is shielded from the air in the cabinet until it is cooled to a temperature about equal to that of the gaseous refrigerant withdrawn from the evaporator ll. The valve 29 and the parts surrounding it are cooled by the evaporation of a portion of the liquid refrigerant passing therethrough to a temperature below that of the surrounding media, and since the temperature of the body of liquid refrigerant within the tube 36 has been reduced to a value below that of the air in the compartment, the heat absorbing capacity of the valve and surrounding parts is available to reduce the temperature within the cabinet.

Although I have shown and described my in- Y vention in connection with a refrigerating system `of a mechanical type, it will be understood that it is also applicable in connection with other refrigerating systems, and I do not, therefore, desire my invention to be limited to the particular arrangement shown and described, and I intend in the appended claims to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A refrigerating system including a compartment to be cooled, an evaporator, a flow con' trolling device in said compartment. means for Y supplying refrigerant to said evaporator through said flow controlling device and for maintaining aI body of liquid refrigerant on the supply side of said ow controlling device, means for reducing the temperature of a portion of said body of liquid to approximately the temperature of the refrigerant in said evaporator, said portion of said body of liquid and said temperature reducing means being separated from parts of said system operating at higher temperature by a body of heat insulating material.

2. A refrigerating system including a compartment to be cooled,.an evaporator, a ow controlling device in said compartment, means for supl plying refrigerant to said evaporator through said flow controlling device andA for maintaining a body of liquid refrigerant on the supply side of said flow controlling device, and means utiliz, 13g ing refrigerant vaporized in said evaporator for cooling a portion of said body of liquid, said portion of s aid body of liquid and said cooling means being separated from parts of said system operating at higher temperature by a body of heat insulating material. y

3. A refrigerating system including a compartment to be cooled, an evaporator, a ow con- I trolling device located in said compartment, means for supplying refrigerant to said evaporator through said flow controlling device and for maintaining a body of liquid refrigerant on the supply side of said flow controlling device, and means utilizing refrigerant vaporized in said evaporator for cooling a portion of said body of 1,15

liquid, said portion of said body of liquid and said cooling means being arranged within* the compartmentto be cooled and separated from parts of said system operating at a higher temperature by a body of heat insulating material.

. 4. A refrigerating system including a compartment to be cooled, an evaporator, a valve in said compartment, means including a chamber having a float therein for supplying refrigerant to said evaporator through said valve and for maintaining a body of liquid refrigerant on the supply side of said valve, means utilizing the movement of said float for controlling said valve, and means utilizing refrigerant vaporized in said evaporator for cooling a portion of said body of liquid refrigerant, said portion of said body of liquid refrigerant and said cooling means being arranged within the compartment to be cooled and separated from parts of said system operating at a higher temperature by a body of heat insulating material. 1

5. A refrigerating system including a compartment to be cooled, an evaporator, a valve in said compartment, means having a float therein for supplying refrigerant to said evaporator through said Valve and for maintaining a body of liquid refrigerant on the supply side of said valve, means for utilizing the movement of said float for controlling said valve, and means utilizing refrigerant vaporized in said evaporator for cooling a portion of said body of liquid refrigerant, and means for insulating said portion of said body of liquid refrigerant and said cooling means from parts of said system operating at a higher temperature.

6. A refrigerating system including a compartment to be cooled, an evaporator, a, valve in said compartment, means having a iioat therein for supplying refrigerant to said evaporator through said valve and for maintaining a body of liquid refrigerant on the supply side of said valve and within said compartment, means utilizing the movement of said float for controlling said valve, and means utilizing refrigerant vaporized in said evaporator for cooling a portion of said body of liquid refrigerant and for shielding the same from the media within said compartment, said portion of said body of liquid refrigerant and said cooling and shielding means being separated from parts of said system operating at a higher temperature by a body of heat insulating material.

7. A refrigerating system including a compartment to be cooled, an evaporator, a valve in direct heat exchange relationship with the space within said compartment, means having a float therein and arranged outside said compartment Yfor supplying refrigerant to said evaporator through said valve and for maintaining a body of liquid refrigerant on the supply side of said valve, means utilizing the movement of said oat for controlling said valve, and means utilizing refrigerant vaporized in said evaporator for cooling said body of liquid refrigerant.

8. A refrigerating system including a compartment to be cooled, an evaporator, means including a float chamber having a float therein for supplying liquid refrigerant to said evaporator, said float chamber being arranged outside of said compartment, a conduit extending from said float chamber, a valve in said conduit Within said compartment, said conduit and said valve being insulated from the ambient surrounding said compartment, means utilizing the movement of said float for controlling said valve, and means utilizing refrigerant vaporized in said evaporator for cooling said conduit and the liquid refrigerant therein.

9.' A refrigerating system including a compartment to be cooled, an evaporator, means including a oat chamber having afloat therein for supplying liquid refrigerant to said evaporator, said oat chamber being arranged outside of said compartment, a conduit extending from said float chamber into said compartment, a valve in said conduit within said compartment, means utilizing the movement of said float for controlling said valve, and means utilizing refrigerant vaporized in said evaporator for cooling said conduit and the liquid refrigerant contained therein.

10. A refrigerating system including a compartment to be cooled, an evaporator, a compressor and a condenser, a float chamber having a float therein and arranged outside said compartment, means for supplying liquid refrigerant from said condenser to said oat chamber, a conduit leading from said float chamber to said evaporator, a valve in said conduit in said compartment, means utilizing movement of said float for controlling said valve, means for returning vapor- .ized refrigerant from said evaporator to said compressor, and means providing a path for heat flow from said last mentioned means toa portion of said conduit located within said compartment and on the supply side of said valve for cooling the liquid refrigerant flowing to said `valve.

11. A refrigerating system including a compartment to be cooled, an evaporator, a flow controlling device arranged in said compartment, means for supplying liquid refrigerant to said evaporator through said ow controlling device and for maintaining a body of liquid refrigerant on the supply side of said flow controlling device and in said compartment, and means utilizing refrigerant vaporized in said evaporator for cooling a portion of said body of liquid and'for shielding the same from the media in said compartment, said portion of said body of liquid and said cooling and shielding means being separated from parts of said system operating at higher temperature.

12. A float operated valve for a refrigerating lsystem comprising a float chamber having a float therein, a conduit extending from said float chamber, a valve in said conduit remote from said float chamber, means utilizing the movement of said float for controlling said valve, and a second conduit in heat exchange relationship with a portion of said rst mentioned conduit between said float chamber and said valve.

13. A float operated valve for a refrigerating system comprising a float chamber having a oat therein, a conduit extending from said float chamber. and having a valve therein remote from said float chamber, means utilizing the movement of said float for controlling said valve, a helical conduit substantially surrounding said first mentioned conduit between the walls of said float chamber and said valve, and means for introducing a cooling fluid into said helical conduitl to cool said conduit.

14. A noat operated valve for a refrigerating system comprising a float chamber having a. float therein, a conduit extending from said -oat chamber, and having a valve therein remote from said chamber, means including a linkage ex-' tending through the interior of said conduit and utilizing the movement of said float for operating said valve, and a second conduit in heat exchange relationship with a portion of said rst mentioned conduit between the walls of said float chamber and said valve.

15. A refrigerating system including a compartment to becooled, an evaporator, a flow-controlling device in said compartment, means including a conduit for supplying refrigerant to said evaporator through said flow-controlling device and for maintaining a body of liquid refrigerant on the supply side of said flow-controlling device; means including a helical conduitl surrounding said conduit for reducing the temperature of a portion of said body of liquid refrigerant to 

